Apparatus for heat treating metal



A ril 24, 1934. .1. THOMSON APPARATUS FOR HEAT TREATING METAL Filed Aug. 11 1931 5 Sheets-Sheet l April 24, 1934 J. THOMSON APPARATUS FOR HEAT TREATING METAL 3 Sheets-Sheet 2 Filed Aug. 11, 1951 a 1 8 2 1 3 0 u 1" fl a7? 9 4 MW 2 n Li, A

had?!- Jnzes 1 7107715010 April 24, 1934. J THOMSON 1,956,519

APPARATUS FOR HEAT TREATING METAL Filed Aug. 11, 1931 3 Sheets-Sheet 5 Lia/r165 .Y'Aamsam 71/414 Patented Apr. 24, 1934 STATES PATENT OFFICE Continental Roll & Steel Foundry 00., East Chicago, Ind., a corporation of Delaware Application August 11,

8 Claims.

My invention relates to apparatus for heat treating metals or the like.

One of the objects of the invention is to provide an advantageous apparatus of the class specified.

Another object of the invention is to provide an apparatus by which localized heat treatment may be advantageously accomplished.

Another object of the invention is to provide an apparatus which may be advantageously used for the localized heat treatment of annular or circular articles.

Another object of the invention is to provide an apparatus which may be advantageously used for the heat treatment of circular or annular objects or articles in such a way that the outer or peripheral portion of the article or object may be made harder and tougher than the remaining or central portion of the object or article.

Another object of the invention is to accomplish the foregoing and other advantageous results in a simple, practical and expeditious manner.

heat treating metals or the like which is particularly adapted for the localized treatment of circular articles, such for example as gear wheels, in such a way that the outer or peripheral portion of the wheel, namely, the teeth and perhaps a small portion of the web or spokes adjacent the teeth, may be heated to a desired temperature, as for example the critical temperature of the material of which the peripheral part of the wheel is composed and by which also the central part of the article such as the gear wheel will be caused or allowed to remain at a lower temperature, the remaining or central portion of the wheel being preferably allowed to come in contact with the outside air and thereby become moderately cool, while the peripheral portion of the wheel is being heated as aforesaid.

This type of apparatus or furnace may be very advantageously used for the heat treatment of gear wheels or the like so that the peripheral portion will be made hard and tough and the central portion softer.

To this end the furnace herein disclosed would be used as stated to heat the gear wheel periphery through the critical range or to any other desired temperature and then the wheel would be taken from the furnace and quenched in a cooling liquid. Preferably the gear wheel is first heated moderately, to or below the critical range, a before being placed in this furnace.

In this application I show an apparatus for 1931, Serial No. 556,395

Although I have disclosed this apparatus or furnace in this application, it is to be understood that I do not wish to be limited to the same, as the invention is obviously applicable to other types and kinds of apparatus or furnaces and to apparatus for heat treating articles other than gear wheels.

In the accompanying drawings Fig. 1 is a plan view of an apparatus adapted to carry out my invention and especially use! ful in connection with the heat treatment of annular articles, such for example as gear Wheels;

Figs; 2 and 3 are details of construction, Fig. 3 being a cross section taken on the line 3-3 of Fig. 1;

Fig. 4 is a side elevation of said apparatus;

Fig. 5 is a vertical section of the same;

Fig. 6 is a plan view of the heating arrangement of the apparatus; and

Fig. 7 is a view of a detail of construction taken on line 7'7 in Fig. 6.

Referring to the drawings I show a furnace A preferably composed of two annular parts or sections 1 and 2, the part 2 being fitted removably upon the part 1. This furnace may be mounted in any convenient manner, as by setting the lower part 1 upon legs or pedestals 3.

Each of the parts 1 and 2 is preferably made annular with an outer or peripheral portion indicated as 4. in the part 1 and as 5 in the part 2 and these two annular portions substantially correspond so that when the part 2 is mounted on the part 1 an annular structure is formed. Each of the parts 1 and 2 has a hollow central portion marked 6 in the part 1 and 7 in the part 2, so that air has free access to and may circulate in and through these central spaces 6 and 7.

The parts 1 and 2 together are preferably provided with an annular chamber 8, Figs. 1 and 5, and this chamber is substantially closed by the annular structures 4 and 5.

This permits a circular article, such for example as a gear wheel 9 to be mounted in this furnace arrangement with its teeth 10 confined in the annular chamber 8 and its central portion consisting of its hub 11 and more or less of its web or spokes 12 to be located outside of the annular chamber 8 and preferably outside of any chamber or part of the furnace, but exposed completely to the outside air by reason of the spaces 6 and '7, Fig. 5.

Arrangement is made for heating the part of the article, such for example as the teeth 10 of the gear wheel 9, while that part of the article or the gear wheel teeth for example is confined in the annular heating chamber 8. done in various ways.

As a simple and preferred arrangement the furnace is shown provided with a plurality or series of heating burners l3 and the outer wall portions of the members 1 and 2 are preferably pro vided with openings or apertures 14 through which the heat from the burners 13 may be communicated to the heating chamber 8. The burners 13 are shown conveniently supported by a circular gas pipe 15 which may be understood to be connected with a suitable source of gas supply so that the burners 13 may be effective in heating the entire circumference of the annular chamber 8 and in this way the annular portion consisting mostly of the gear Wheel teeth 10 which are confined in the heating chamber 8.

In this way the temperature of the annular portion or teeth of the gear wheel under treatment may be heated to any desired temperature and held at that temperature as long as desired While at the same time the central part of the This may be Wheel will be subject to the cooling influence of the outside air by reason of air spaces 6 and '7.

In Fig. 3 a detail of the heating arrangement is shown merely for the purpose of better understanding;

Preferably the upper member 2 is provided with vents 16 by which the heating chamber 8 may be vented to a certain desired extent. Also lugs or clips 19 are provided on the upper member 2 for the purpose of allowing said upper member to be raised and lowered as desired, said clips 19 being provided wtih apertures 20 for hooks of a lifting device or crane.

In carrying out my invention in connection with apparatus of this kind, the article under treatment, such as a gear wheel, is placed in the furnace in the manner shown in Fig. 5, wherein said article if it is a gear wheel has its teeth 10 confined in the annular chamber 8 and its central portion open to the air because of the central spaces 6 and '7, and the article is then heated by the burners 13 to the extent desired. In carrying out the invention to accomplish certain desired results in circular or annular articles, such for example as gear wheels, the article such as the gear wheel is first heated in a separate furnace or heating device and the article is heated in this way to a certain predetermined temperature, as for example, to or below the critical range of the material of which the wheel is composed. Then the article is transferred to the furnace or apparatus A herein shown and the rim or peripheral part thereof is further heated, as for example through the critical range of said material. After being thus heated, the article or wheelmay be taken out of the furnace A and quenched in a liquid bath or otherwise cooled, thereby hardeningand toughening the rim portion and giving the central portion the soft and elastic qualities desired for machining and shock resisting.

While this furnace will serve to illustrate the invention, it is understood to be understood that the invention may be applied in various other ways.

I claim:

1. An apparatus of the class specified comprising relatively thick centrally recessed top and bottom sections having complemental recesses formed between inner and outer marginal walls adapted to provide a heating chamber intermediate said sections, the outer marginal walls of the sections being adapted to abut together and the inner marginal walls being spaced to fit closely an article to be treated while a portion thereof is adapted to be exposed to the heating chamber, means: for applying heat uniformly to that portion of the article exposed within the heating chamber, and a cooling chamber formed by the centrally recessed portions of the sections for receiving the remaining portion of the article.

2. An apparatus of the class described comprising relatively thick centrally recessed top and bottom sections having complemental recesses formed between inner and outer marginal walls adapted to provide a heating-chamber intermediate said sections, the outer marginal walls of the sections being adapted to abut together and the inner marginal walls being spaced to fit closely an article to be treated while a portion thereof is adapted to be exposed to the heating chamber, a series of heating means for applying heat uniformly to that portion of the article exposed within the heating chamber, and a cooling chamber formed by the centrally recessed portions of the sections for receiving the remaining.

portion of the article.

3. An apparatus of the class described comprising relatively thick centrally recessed top and bottom sections having complemental recesses formed in each of said sections between inner and outer marginal walls to provide. a heating chamber, the outer marginal walls being adapted to abut together and the inner marginal walls being spaced to fit closely an article to be treated While a portion thereof is adapted to be exposed to the heating chamber, a series of narrowly spaced conduits leading to the heating chamber, separate heating means for applying heat through each of said narrowly spaced conduits, and a cooling chamber formed by the centrally recessed portions of the sections for receiving the remaining portion of the article.

4. An apparatus of the class described for quick heating metal articles comprising relatively thick centrally recessed top and bottom sections having complemental recesses formed therein to provide a heating chamber, a seat provided on one of the sections adapted to support the article to be treated, a seat provided on the other section adapted to contact with the opposite face of the article to be treated, a series of heating means for applying heat to the chamber, and a cooling chamber formed by the centrally recessed portions of the sections and separated from the heating chamber for receiving one part of the article while the remaining part is exposed to the heating chamber.

5. An apparatus of the class described for quick heating metal articles comprising relatively thick centrally recessed top and bottom sections having complemental recesses formed therein to provide a heating chamber, a seat provided on one of the sections adapted to support the article to be treated, a seat provided on the other section to contact with the opposite'face of the article to be treated, a cooling chamber formed by the centrally recessed portions of the sections and separated from the heating chamber for receiving one part of the article while the remaining part is exposed to the heating chamber, and means on one section adapted to receive a lifting device for assembling and disassembling said sections with the other section.

6. An apparatus of the class described for quick heating metal articles comprising a centrally recessed top and bottom section having complemental recesses adapted to provide a heating chamber therebetween, means for supporting an article to be treated on the sections, a series of conduits leading to the heating chamber, a cooling chamber formed by the centrally recessed portions of the sections and a series of burners adjacent said conduits adapted to impinge flame heat directly upon the portion of the article to be treated in order to heat same quickly and uniformly to a high temperature.

'7. An apparatus of the class described for quick heating metal articles comprising centrally recessed top and bottom sections having complemental recesses adapted to provide a heating chamber therebetween, means for supporting an article to be treated on the sections, a plurality of narrowly spaced conduits leading to the heating chamber, a cooling chamber formed by the centrally recessed portions of the sections and a series of burners adjacent said conduits adapted to impinge flame heat upon the portion of the article to be treated in order to heat same quickly and uniformly to a high temperature.

8. An apparatus of the class described for quick heating metal articles comprising centrally recessed top and bottom sections having complemental recesses adapted to provide a heating chamber therebetween, means for supporting an article to be heated on one of the sections, a plurality of conduits leading to the heating chamber having flared nozzles diverging around the portion of the article to be heated, a cooling chamber formed by the centrally recessed portions of the sections and a series of burners adjacent the conduits adapted to impinge flame heat upon the portion of the article to be treated in order to heat same quickly and uniformly to a high temperature.

JAMES THOMSON. 

